Monitoring left ventricular dilation in mice with PET.

Molecular imaging by small-animal PET is an important noninvasive means to phenotype transgenic mouse models in vivo. When investigating pathologies of the left ventricular (LV) myocardium, the serial assessment of LV volumes is important. By this, the presence of LV dilation as a sign of developing heart failure can be detected. Whereas PET is usually used to derive biochemical and molecular information, functional parameters such as ventricular volumes are generally measured using echocardiography or MRI. In this study, a novel method to monitor LV dilation in mice with PET is presented and evaluated using cardiac MRI. METHODS: A semiautomatic 3-dimensional algorithm was used to delineate the LV myocardial wall on static PET images depicting myocardial glucose metabolism ((18)F-FDG PET) for 20 mice: 10 wild-type and 10 genetically modified littermates designed to develop a dilative cardiomyopathy phenotype (cardiomyocyte-specific knockout of survivin). The volume enclosed by the 3-dimensional midmyocardial contour was calculated as a measure for LV volume for each mouse. Data were compared with ventricular volumes measured by MRI in the same animals. RESULTS: LV volumes obtained by PET and MRI correlated well (R = 0.89) for hearts with small and large left ventricles. In accordance with the hypothesis, the LV volumes were increased significantly for transgenic mice examined at an older age compared with those examined at a younger age (MRI: 160.5 +/- 25.7 microL vs. 114.7 +/- 15.2 microL [P = 0.012]; PET: 129.3 +/- 15.3 microL vs. 73.8 +/- 15.0 microL [P < 0.001], all values shown as mean +/- SD; for MRI, mean of end-diastolic and end-systolic volumes are given), whereas they did not for their wild-type littermates (MRI: 106.2 +/- 12.3 microL vs. 94.7 +/- 14.6 microL [P = 0.214]; PET: 82.6 +/- 20.9 microL vs. 65.0 +/- 16.9 microL [P = 0.185]). CONCLUSION: Evaluation and quantitation of LV dilation in both control and cardiomyopathic mice can be reliably and serially performed using small-animal PET and (18)F-FDG, yielding useful functional information in addition to metabolic data.     

Assessing quality of life in primary biliary cirrhosis.

BACKGROUND AND AIMS: Assessment of health-related quality of life (HRQOL) is not routinely reported in the literature on chronic liver disease (CLD). Few studies have examined quality of life (QOL) in patients with primary biliary cirrhosis (PBC) despite its significant functional impact. One of the reasons for the lack of HRQOL measurement in patients with PBC may be the absence of a well-recognized and widely used measure that clinicians can use in ordinary clinical practice. The aim of this study is to evaluate HRQOL measures used in patients with PBC and examine the suitability of the measures for these patients. METHODS: A literature search identified reports that focused on any aspect of QOL in patients with PBC. Key texts were identified containing generic, domain-specific, and condition-specific measures. The identified measures were systematically evaluated for appropriateness, acceptability, reliability, validity, precision, and responsiveness. RESULTS: Twenty measures were identified from 9 key texts. Six of the measures were previously validated generic measures; 10 were domain-specific measures previously used to measure fatigue, depression, and psychological distress in general and psychiatric populations; and 4 measures had been developed in patients with CLD. Reporting of reliability and validity generally was consistent for all measures used. However, reporting of the remaining criteria was variable, particularly in relation to responsiveness over time and acceptability of the measures to patients with PBC. CONCLUSIONS: A clearer and more rigorous approach is needed in reporting the properties of HRQOL measures used in patients with PBC to help clinicians decide which measures are most suitable for these patients.     

Shear stress related blood damage along the cusp of a tri-leaflet prosthetic valve.

Blood flowing through a prosthetic heart valve can be damaged by flow-induced shear forces. Fluid dynamics variables and geometric factors play an important role in the evaluation of shear-stress-related blood damage. Central-flow prosthetic valves have been considered as an optimal replacement for mechanical and biological valves. Recently it was shown that shear stress distribution along the surface of a polyurethane cusp reaches values that can damage the blood elements. A mathematical model correlating the effects of shear stresses on blood corpuscles with clinical findings was employed in vitro. The model can be applied to the effects of blood-surface interaction and is of clinical relevance.     

Development of a Novel Scale to Assess Life Fulfilment as Part of the Further Refinement of a Quality-of-Life Model for Epilepsy

Summary: We have been involved in developing a health-related quality-of-life model for use as an outcome measure in epilepsy. As part of the further development of this model, we have developed a measure of life fulfilment. This scale is based on methods previously described by Krupinski in 1980. The value of Krupinski's approach is the opportunity for patients to weight the numerous aspects of their quality of life and assess the discrepancy between their actual and desired circumstances. The life fulfilment scale has been shown to be reliable (α= 0.7) and valid. The scale is currently being applied to several clinical studies in epilepsy. We believe that the scale provides a valuable contribution to our health-related quality-of-life model.     

Molecular study of frequency of mosaicism in neurofibromatosis 2 patients with bilateral vestibular schwannomas

Neurofibromatosis 2 (NF2) is a severe autosomal dominant disorder that predisposes to multiple tumours of the nervous system. About half of all patients are founders with clinically unaffected parents. The purpose of the present study was to examine the extent to which mosaicism is present in NF2 founders. A total of 233 NF2 founders with bilateral vestibular schwannomas (BVS) were screened by exon scanning. NF2 mutations were detected in the blood samples of 122 patients (52%). In 10 of the 122 cases, the ratio of mutant to normal alleles was obviously less than 1, suggesting mosaicism. Tumour specimens were available from 35 of the 111 subjects in whom no mutation could be detected in blood specimens. Mutational analysis by exon scanning detected typical NF2 mutations in 21 of the 35 tumours. In nine subjects, the alterations found in tumours could be confirmed to be the constitutional mutation based on finding of identical mutations in pathologically and/or anatomically distinct second tumours. In six other subjects with only a single tumour available, allelic loss of the NF2 gene was found in addition to the mutation in each tumour, suggesting that either the mutation or the deletion of the NF2 gene is probably the constitutional genetic alteration. Our results suggest that failure to find constitutional mutations in blood specimen from these 15 patients was not because of the limitation of the applied screening technique, but the lack of the mutations in their leucocytes, best explained by mosaicism. Extrapolating the rate (15/35 = 43%) of mosaicism in these 35 cases to the 111 NF2 founders with no constitutional NF2 mutations found in their blood, we inferred 48 mosaic subjects (111 x 0.429). Adding the 10 mosaic cases detected directly in blood specimens, we estimate the rate of mosaicism to be 24.8% (58/233) in our cohort of 233 NF2 founders with bilateral vestibular schwannomas.     

Natural Clostridium botulinum type C toxicosis in a group of cats

Clinical signs of botulism were observed in a group of eight cats, four of which died, after being fed pelican carrion. Clostridium botulinum type C was isolated from one cat. The microorganism and its toxin were found in the pelican. This is apparently the first report of natural botulism in cats.